Electric switch



Aug. 14, 1934.

R. A. MILLERMASTER ELECTRIC SWITCH Filed March 28. 1932 5 Sheets-Sheet 1 Aug. 14, 1934.

R. A. MILLERMASTER ELECTRIC SWITCH Filed March 28, 1932 3 Sheets-Sheet 2 Aug. 14, 1934. R. A. MILLERMASTER ELECTRIC SWITCH Filed March 28, 1932 3 Sheets-Sheet 5 Patented Aug. 14, 1934 1 UNirEosrArss PATENT oFFica V 1.97o,244 ELECTRIC SWITCH Ralph A.' Millermas ter, Milwaukee, Wis, assignor' to Cutler-Hammer, Inc., Milwaukee, Wis.', a corporation of Delaware J 1 ;-Application March 28, 1932, s rial No. 601,525 1s Claims. (01. 200-50) This invention relates to improvements in elec- Fig. 7 is a plan view of the switch operating tric switches, and jmor particularly to enclosed handle prior to a t m thereof to the Shaft. or safety switches'of the fused type." Y and An object-of the invention is to generally im- Fig. 8 is a similar view of the handle at right prove and s' implify' the' construction, assembly angles to the view of Fig. I. g and operation of switchesofthe aforementioned Referring to the drawings, thenumeral ,10 characterfi I designates in general a relatively shallowbox-like. Another object is to provide novel and improved sheet metal casing having a bottom wall 11, side means for carrying and operating the movable walls 12 and 13 and end walls 14, and=15,- the contacts of the switch. V end wall 15 being preferablyof the removable or "Another object is to provide a fused safety .snapdn yp as indicated y theformationof switch wherein the parts are so arranged as to the flanges a 16 in Figs- :2 and.-3,'I1l1t and bolt permit use'of'a 'r enclosing casing ofrnininiu'm devices'17being preferably provided to rigidly depth. t? 1 secure said end wall in position. :Said casing is 15 Another object/is to provide an arrangement also provided with an openable cover 18, which as whereby the movable switch parts may be asshown is of flat formation and hinged to. the cas sembled with respect to the casing'entirely inde ing at 19 and 20 (Fig.1). pendently of the other parts of the switch} The side wall 12 of the casing is provided with Another object i s to providea iiovel and a'circular opening 21 (Fig. 4) of a size to permit '20 arrangement'of the stationary'c'ontacts and terready inserti n of nd o pr vid a ear n for '1 minalelements of-the switch'whe'reby said 'eleone end ofthe shaft 22, which asshown is of ments maybe removed'andreplacedwithout'dissquare C oss ecti th ughout the major D turbing the otherparts of the device. tion of the length thereof,-the forwardend, of

Anotherobject is to provide a novel form of fuse said shaft being of reduced cylindrical cross sec- 25 chamber for the device. tion (as shown at 23 in Figsl and'4) to fit Another object is'to provide-novelmeans for within an alined circular bearing opening of controlling access to said fuse chamber. proper size provided in the side wall 13.

Other objects and advantagesof the invention Shaft'22 is provided with a one-piece stamped will hereinafter appear. sheet metal handle 24 of the form best illustrated .30 The accompanying drawings illustrateiianemin Figs-7 and 8. I The flat lower end portion of bodiment of the invention which will now be desaid handle is provided with a square opening scribed, it being understood that the embodiment 25 which is adapted to 'fit snugly onto the square illustrated is susceptible of modification in certain shaft 22 in a relation flush with one end of the details thereof without departing from the scope latter, as shown in Figs. 1 and 4. The handle 35 of the appended claims. f 24 is then welded to shaft 22 at points inter- In the drawings, Figure 1 is a plan view of a mediate the four flat sides of the latter, as indifused safety switch' constructed in accordance cated at 26 in Fig. 4, whereby said parts are with my invention-the main cover member rigidly and permanently united to each other. thereof being shown in fully opened position. This arrangement of the weld-spots 26 permits 40 Fig. 2 isasectional view'on the broken line 2- 2 positioning of the lower portion of handle 24 of Fig. 1. b flush against one side of a washer 27 which is Fig. 3 is a sectional view, on the line 33 of strung upon shaft 22,the other side of. said Fig. 1. washer being positioned against the outer sur- Fig. 4 is a perspective view of the movable parts face of side wall 12. A washer 28 is strung upon 45 of the switch shown in Figs. 1, 2 and 3, and illusshaft 22 and adapted to lie against the inner trating the manner in which said parts may be surface of wall 12,said shaft being provided assembled. with a transverse opening 29 to receive a cotter Fig. 5 is a fragmentary sectional view, on the pin 30 or other securing element whereby the line 5-5 of Fig. 1, showing the latching means shaft 22 is held in assembled relation to the 5 for releasably holding the sliding plate in one metal casing.

of its extreme positions. Prior to insertion of cotter pin 30, however, a Fig. 6 is a perspective view of one of the duplipunched and stamped sheet metal member 31 cats molded insulating members which jointly is strung upon shaft 22, said member having provide a partial enclosure for the fuse recepa square opening to provide an interlocking con- 55 tacles of the device. nection between the same and said shaft, and

said member having its free end portion 31 of reduced width and bent on a slight bias to extend laterally in a plane at right angles to the plane of the body portion thereof. Member 31 provides an interlocking connection between shaft 22 and a movable part of the casing, as hereinafter described v v Also ,slidable "onto shaft 22 is a tube 32 of square cross section whereby the latter is interlocked with the former for rotation" therebyf" Tube 32 is formed of insulating material prefer: ably of the phenol formaldehyde condensation type sold commercially under the trade name of bakelite. Slidable onto .tube, 32 in the manner,

illustrated in Fig, 4 are theg l'cylindrical jniolded punched sheet metal eontactors alld 3 7, m81fl ber 33 having an end recess td reeive'thecir cular body portion 36 and portions ot'tharadial arms 36 36 in a substantially flush relation and tofip'ermit aslight amount of 'lateral movement 'ofL-said contact arms relatively tosaid Member 34 is provided with a similar:

member. e'nd recess 5 to accommodate the corresponding parts of contactor 37.

-' 'I'he aforemeantionedcylindrical insulating members and theicontactors are provided-with square openings or p'assa'ges whereby'the. same are interlocked withtube '32 for rotation or oscillation'thereby. As best illustrated inhFig. :2

the longitudinal icerit'erlines. of v the radial arms 36", 36 of contactor: 36 are spaced apartzthrough an arc of *subs'tantially' "bne hundred thirty-seven degrees,- -an'd3 the" centrally; locatedfisquare opening in the'contactor iaso arranged thatctwo -of. the sidesof saidfropening are-in planes parallel to the longitudinal centerline of arm 36:v In.

this 'conn'ectionzit, willrbenoted from' Fig;-. 7 that thewalls of'the squareopening 25. in handle 24 are so 'arranged angularly with respecttothe.

J 37 within the end; recess of; member 34. The

non-adjacent edges of the contactor arms are chamfered or beveled, asgindicated at 36 36 and 37 3'7 in-Fig; 4, to facilitate engagement thereof with resilient'stationary contactsvof reflexed form. Said contacts aredesignated by the-numerals 38, 39, 40"a'nd 41 and the same are of identical form with respect to each other. The contacts' 38 and 40 are secured to an insulating base member 42 which is in turn 'secured to the bottom wall 111 of the casing as by'means of a pair of screws 43 and 44. The manner of attaching the contact 38 to base 42 is best illustrated in Figs. 1 and 2, wherein 1 have shown a bus member having an angled end portion 38 to which the contact is rigidly secured as by means of a rivet 38 The other end 38 of said bus member is adapted to overlie the ledge portion 42 formed on base 42, said portion as shown having an opening therethrough to provide clearance for a screw 42 the head of which is locatedv within a countersink in the lower surface of said base,said screw. head being restrained against longitudinal movement within said countersink as by means of a quantity of wax or cement 42. Threaded onto the shank of screw 42 is a nut 42 which acts to clamp bus member 38' and contact 38 in position-said contact being located within a recess 42 andt restrained by the walls thereof against lateral displacement. Strung upon the shank of screw' ,-';42F and contact 38 with its associated bus member may readily be removed for repair or replace- 'ment'by='merely removing the nuts 42 and 42 without. disturbing anyiof the other parts of the ,deyice. ii lieTfacilityiwith which the stationary insulating members 33, 34 and and the fiat contact and terminal members may be removed and replaced is oi importance from a practical viewpoint.- The contact and its associated terminal element are secured to base 42 in a like manner, as'best illustrated in Fig. 1.

C ontact 39 as shown in Figs.- 1 and2-is adapted to straddle theouter end of a-bus member 45;- a wiring terminal -member 45 :being superimposed upon the flat pq ftionot,saidcontact, and a screw 51 hav n l h e eeneas m m th m e fl i r idl zc asip h c fi i nd-mam: ber 45 thereto. A binding screw 45 hasthread; ed engagement withthepifset portiomof member 45*. Bus member 45,is secured to the insulating base member 46 as by means of apair-of screws 47 and :48, scre w 47 having threadedaenga gement with said bus, member and screw 48 being adaptedto penetrate, saidbus member and ithe fiat portion of a fuse clip 49 of known form and i s zm tQ-mt n a d P t ina s mbled relation.- Contact 41 ancl'itsassociated parts includinfg fuse clips 51, aresecuredtobase 46 in a like manner,, as illustrated in Fig, 1. B ase;46 ;is supported within the; metal casing in 1 planes ,oii set upwardly and laterally with ,respect to the; center line of shaft 221. The-support therefor preferably comprisesa plate 52 to which the same is attached as by means of a plurality of screws v53,- the. plate. 52 having end flanges 52 52 whereby the samemay be attached to the side walls 12 and 130i the casing as by means of rivets 54.. i

Also securedtoithe,b'asev 46 area pair of terminal bus members 55 and 56 to the inner ends of which are secured the fuse clips 57 and 58 and to the outerends of which are secured the terminal elements-59 and 60, respectively. Arranged upon base 46 in .a mannerto partially enclose the longitudinally alined sets of fuse clips 49, 57 and 51, 58 are a pair of molded insulating members 61 of -.like.form, said members being-of substantially U-shape' in horizontalcross section, and each is provided at opposite ends thereof with integral lugs 61%, 61*;which lugs are formed to provide for attachment of said membersto said base as by means of screws 61 the shanks of which take into nuts (not shown) located within countersunk recesses in the bottom surface of base 46. One of the members 61 is shown in perspective in Fig. -6,the same being provided in the bottom surface thereof with channels 61 61 to accommodate the bus members associated with the terminal clips 49, 51 or 5'7, 58 aforedescribed. As will be noted the members 61 are arranged with the open ends thereof opposed to but substantially spaced from each other to facilitate removal of fuses (either manually or by means of a suitable tool) from the respective longitudinally alined sets of clips. Also as will be noted the end wall portions of members 61 are interposed between said clipsand theirrespective wiring terminaIssaid walls extending upwardly from base-'46 .to a plane-substantially flush with the upper edgesof the side walls 12 and13 of the As shown in Fig.1,bas'e' 42 is'provided with a recess or pocket 62 within which are located aplurality'of line terminals such as 63, 64 for the neutral'wire of a three-wire system; "said terminals being electrically connected to 'a' plate or'bus member 65"which is secured withinsaid' recess asby-means of a screw '66; Terminal 64 and a meter-test clip 6'7-are'attached'to plate 65 as by means 'of screw 68. A suitable'grounding wire terminal "69 may be attached to'the bottom wall 11' of the casing as by means'of'a screw '70;

- The main portion of the switch operating handle 24' is offset outwardly' from the lower end portion thereof which 'is'attached to-shaft 22, ands'aid main body portionis provided wi'th'an opening 24whichis adapted to selectively register with 'suitably positioned 'openings (not shown) a bracket '71 whereby handle 24 may be locked in either of its "extreme-positions through the medium of a suitable pad-lock (not shown) The bracket'Zl may be attached to the side wall 12 of the casing as by means of rivets '71. The upper endportion 24 o f' handle 24 is behtoutwardly atsubstantially right angles to the main body portionthereof, and said bent "end is further' bent" to segmental formin cross section, as indicated at 24 in Fig."'7 toprovide' a proper hand grfp" for manipulation thereof.

The "main cover 'member"l8 of the casing is provided with}. "substantially rectangular opening '72 which-is adapted to provide access to the fuse receptacle under certain conditions'when :said cover --is--closed, --it' being noted that said opening is slightly enlarged-at the-points 'vz gvz to give 'fulleffect'to the aforedescribed' spacing of the adjacent ends" of' insulating members 61 for facilitating removal of fuses from the fuse clips. A plate 73 lof'greater dimensions than the opening] '72 is slidably mounted uponthe lower surface'of cover 18;- -said plate being retained "and guided for longitudinal movement into and "out of register with opening??? by means of apair of strip metalmembers'ii and '7 5 the opposite ends of whichare respectively offset toward the lower surface of cover i8, and riveted thereto as by means of rivets 74374 and '75 '75". Plate '73 is provided at opposite longitudinal edgesthereof with downwardly extending flanges 73 '73 which engage theouter edges of members '74 and '75 to insure rectilinear movement of theplate. n

Plate '73 is provided with a pair of openings '73, '73 and the members '74, '75 are provided with inwardly extending bosses orprojections 74%.75? adapted to snap into said openings for'releasably retaining plate '73 in its upper extreme position as shown in dotted lines in Figs. 1 and 5. Arranged flush with the upper edge of opening 72 and spaced from cover 18 just sufficiently to accommodate the upper edge of plate '73 is a guard member 76, the latter having an offset portion "76 which is spot weldedor otherwise rigidly and permanently secured to the lower surface of .said

cover. I s

Rigidly secured to plate '73 andprojecting outwardly through cover l8.is ahandle -'7'7,-the cover 18 being provided with a slot 18 to accommodate handle '77 in the lower extreme position of plate '73. and thela-tter having an integral lug 73 to' insure closure of slot 18 in th 'upper extreme position of said plate.

.The flange '73 of plate.'73 is of the special form best illustrated in Fig. 3 whereby thesame is adapted for cooperation with the bent end 31 of member 31 to-provide a proper interlocking connection between the plate '73 and the movable parts of the switch. Thus assuming open positioning of the switch contacts (as represented by thedotted line position of the switch'operating handle 24 in Fig. 1) and assuming positioning of plate '73 as shown in fulllines in Fig. 1, it will be apparent that upon closing of cover 18 the opening '72 therein will be uncovered to provide access to the fuse receptacles. This relative positioning of the parts is shown in Fig. 2,and as indicated by the relative positions of flange 73 of :plate 73 and thebent end '31 of member 31, it is not possible to efiect closure of the switch contacts pendingmovement of plate '73 to its upper extreme position, whereupon access to the fuse receptacles is prevented;

In like manner upon closure of'the. switch contacts, asirepresented by therelative positionsof the parts in' Fig. 3, the bent .end 31 of member 31' will beylocatedin the path of :fiange '73 to prevent movement of plate '73 to its lower extreme position (wherein access to'thefuse receptacles is provided) pending movement of the switch contacts to open position. l .:As shown in Fig. 1 the side wall 12 of the casing has-rigidly-attached thereto; as by spot welding, the lower end of a'resilient latch member '78 for the cover 18,- the latter having an opening 18 to provide. clearance for said latch member. The upper end of member '78 is provided with the usual relatively large and relatively small openings (not shown); the large openingbeing adapted to receive the-hasp of a padlock whereby cover 18 may be locked in closed position, and the small opening cooperating with the loop 18 sheared and bent upwardly from cover 18 to receive the wire portion of asealing element of usual form. The bottom Wall ll'of the casing is provided with a. pair of keyhole slots '79 at its upper end and a pair of double-keyhole slots 80 at its lower end to facilitate attachment of the casing to a wall or other support as by means of suitable screws.

. While I-have described the contactors 36, 3'7 and insultingmembers 33, 34 and 35 as being clamped in assembled relation to each other. it is tobe understood, as aforeindicated, that the end recesses in members 33. 34; (as, for instance, the recess 33 shown in 4) are of suificient endwise depth to permit a slight degree of lateral movement ofthe contactors 36, 3'7 therewithin,-- thus providing a sort of floating support for the latter which renders the same self-alimng to compensate for any inaccuracy in the positioning of the stationary contacts of the switch. I

Secured to the bottom wall 11 of the casing in any suitable manner is a substantially rectangular plate 81 of a suitable fibrous insulating material, such as that sold commercially under the trade name of conite. As shown plate 81 has one end thereof clamped beneath the base 42, the other end of said plate being adapted to underlie the radial arms of the contactors 36, 3'7 in all positions of the'latter to protect the bottom wall f relation to each other and" in? a given-adjusted position longitudinally "ofshaft-22-by a pairof substantially U shaped metal clamps82 and 83,- said clamps having clearance openings 182 ,83 in the upper arms thereof andtapped openings 82", 83 in the lowerarms thereof for cooperation with screws 82, 83s. By assemblingethe-clamps 82;:83 upon shaft 22 in .the manner illustratedthe heads ofthe screws 82, 83."are -readi1y accessible to provide 'for '*removal :or replacement-' of any of the: movable. parts .of the switch :upon opening of the cover. 18, and, as aforedescribed, without disturbing. any of the other partsof the device; 'wWhat-I claim as'new andfidesire to-secure by Letters-Patent'iszxi n1 1;-:'In electric switch linxcombination, an operating 'ShEiftiOf angular cross sectlon,' a tubuilar insulatingsmember of isimilar'cross :section slidably mounted upon said shaft, a fiat punched sheet :metal'contactor slidably engaging saidinsulating member and interlocked therewith fOITOr tation thereby, a pair of molded. insulating members arranged on opposite sidesvof J said contact member and adapted std-expose 'the :blade-portio'ns of the latter, .said last mentioned insulating'frhembers ialso shaving ri'nterlocking engage menttwith' 'said first mentioned insulating meme Lber, and clamping? means for: 1 restraining 5 said partsffrom substantial" movementlongitudinally of said shaft.

-2. -In ani electricswitch; Lin combination,'-an-operating' shafti'of -substantially re'ctangular cross section 3* throughout the major portion of the length-thereof,:.a"lever-:secured to one end "of said shaft, a. tubular member-formed of insulating'rna; terial' of thei'phenokforinaldehyde condensation typegsaid insulatingmember being of rectangular cross section-to 'slidably engage said shaft and to interlock therewith for rotation thereby, a' plurality' of fiat punched sheet 'm'etal ontactors and a plurality ofrmolded' insulating' members 'arranged 'on opposite sidesofand between said contactors, said contactors and'said last mentionedinsulating members havingrectangular openings to provide for sliding engagement and interlocking thereof with'said first mentioned insulating member, all of said parts being simultaneously adjustable longitudinally' of said shaft, and a pair of clamping devices engaging said shaft and arranged at opposite ends ofsaid parts to retain the latter in adjusted position with respect to said shaft.

3 3. In anelectric switch, -in combination, an operating shaft of substantially rectangular cross section throughout the major portion 1 of the length thereof, a one-piece stamped sheet metal actuating lever having 1 a rectangular opening formed therein to snugly fit over said shaft -in a relation substantially flush with one-end of the latter, said lever being welded to said'shaftat points intermediatethe width of the fourflat sides 'of'the latter whereby said parts are rigidly and permanently united to each-other, a sheet metal-casing having a circular opening in one side wall thereof to accommodate said shaft and to provide a bearing for the rectangular portion thereof adjacent to'said lever, awasher strung upon said shaft and arranged against the outer surface of said side wall and against the inner surface of said lever, a second washer strung upon saidshaft and arranged against the inner surface of aid side wall, said shaft having a transverse passage located in a plane adjacent to the inner surface of said last mentionedwasher,aremovable element penetrating said passage and adapted to maintain saidshaft, assembled relation toosaid bearing opening, the other-end of saidshafthav- -:ing a reducedend-of cylindrical-contour, and the other side: wall of, said casinghaving a circular opening alined with said first mentioned opening and adapted to-provide a :bearing for-the last mentioned end of-said shaft.. 1; A. In lan electric switch, incombinatioma box- ;likellsheet; metal casing having alined bearing openings formedinaopposite side walls thereof, an Operatingi ishaft; sofnrectangular;.-crosssection insertable, into said casing through one,of;.;said bearing openings,';-apunched and, stamped ,sheet metalmember having a rectangular opening and a tubular insulating-member of rectangular: cross section. to be strung sequentially upon :said shaft,

I said sheetmetal member 3 being adapted-do, prowide, a releasable V interlocking connection with oneof the casing parts, a plurality of :moldeda'nsulating cylinders r and a-rplurality of punched sheet metal contactorsinterposed-,therebetwflfin and spacedthereby, each ofsaid ;cylinders and said contactors having -;a rectangular; opening :therethrough-to provide for; interlockingengage mentthereof-,with said ,insulatingtube; all; of; gsaid parts" being normally-adjustable as a group longitudinally ofsaid shaft to bring -zthe; same into registrywith other parts of ;the switch apairof clamping devices :engaging said ,shagft at opposite ends-of said groupgof parts ltorestrain the latter against movement longitudinally-mfg said? shaft, said shaft having a reduced cylindrical: end to engage the other of said bearing openings, and means associated withnsaid shaft ,to normally prevent; longitudinal; displacement; thereof a in either directionwith respect to said side gwalls of the casing. f

4 5. In-an electric switch, in combinatiorna box- .like sheetmetal casinghaving, alined bearing openings .formed in .ppposite, s ide walls-(thereof, a operating h t e se n a sr e sa iienmsortable intosaid casing through one .of said bearing openings, a punchedland stampedfsheet rnetal member having a rectangular opening and, a tubu lar insulating member of rectangular cross section to be strung's'eque'ntially,uponsaid'shaft, said sheet metal Inernberfbeing adapted to provide. a releasable interlocking connection with one of the casingpartsa plurality of molded insulating cylinders ahd a'plin'alityof punched sheet metal 'con'tactorsv interposed .therebetweenf and .spaced thereby, each'of said cylinders and said'contac'tors having a rectangular opening therethrough .to provide for interlocking'lengagement thereof with said insulating tube, all of, said partsbeing normally adjustable as a group longitudinally of-said shaft to bring the same into registry with other partsof the switch, .a pair of clamping. devices engaging said shaft at opposite ends of said group of .parts to restrain the latter against movement longitudinallyof said shaft, said shaft having a reducedcylindrical end to engage the other of said bearing openings, and. means associated with said shaft to normally prevent longitudinal displacement thereof in either direction with respect to said side walls of the casing, said means including means remcvablefrom said shaft to permit longitudinal displacement of the latter in one direction at will.

6. In an electric switch, in combination, a boxlike sheet metal casing having bottom, side and end walls and an "op'enable cover, a shaft having the major portion of the length thereof of square cross section, said side walls having alined open ings to provide for endwise insertion of said shaft ihtosaidcasing forbearing engagement with said openings; a tubular insulating, member of square crosssectionslidable onto said shaft, a plurality oft-flat punched .sheet metal contactors slidable onto said insulating ,member and interlocked therewith for rotation thereby, a plurality of molded insulating cylinders also interlocked with saidinsulating member and arranged" on opposite sides of and between said contactors to space the latter relatively to eachother and to assist in insulatingzthe same, each ofsaidcontactors havingoaipairiof arms extending radially beyond said insulating cylindersyansinsulating base secured to thebottomiwallxof :saidcasing,- a second 'insulating b'asesecured within said casing in a'plane above the longitudinalcenter line ofsaid shait, a -plurality of stationary contact and terminal members-securedxto each of said'insulatin'gbases; and: means for effecting oscillatory movement of said shaft to bring said contactors into and out of bridging :enga'ge cut with said stationary'con o 1 1' L In-an electric switch, in combinationya boxlike sheet metal casing having bottom, sideand i end walls and an openablecover, a shaft having the'majorportionfof the length thereof of square cross section, said side "walls having alined 'openings't'o "provide'for endwise insertion of said shaft into-said casing for hearing engagement with'said openings, a tubular insulating member of square cross'secti'on slidable'onto said shaft, a plurality of-fiat' punched sheet metal contactors slidable onto' said insulating member and interlocked therewith 'for rotation thereby, a plurality of Z molded insulating cylinders also interlocked with cured to thelbottom wall'of said-casingQa second insulating-base secured within said casing in-a plane above thelongitudinal center line of said shaft,,a pluralityof stationary contact and terminal members secured to each of said insulating bases, and means for effecting oscillatory movement of said shaft to bring said contactors into and out of bridging engagement with said stationary contacts, each of said contact and terminal members being accessibly positioned within said'casing to provide for removal and replacement thereof individually without disturbing any of'the other parts of 'the switch.

'3; In an electric switch, in combination, a boxlike sheetmetal casing having bottom, "side and end walls and an openable cover, a shaft having the major portion of the length thereof ofsquare cross section, said sidewalls having alined openlugs to provide for endwise insertion of said shaft into said casing for bearing engagement with said openings, a tubular insulating member of square cross section slidable onto said shaft, a plurality of fiat punched sheet metal contactors slidable onto said insulating member and interlocked therewith for rotation thereby, a plurality of molded insulating cylinders also interlocked with said insulating member and arranged on 'opposite, sides of and between said contactors to spa'cethe latter relatively to each other and to assist in insulating the same, each of said contactors havinga plurality of arms extending radially ,from a common center at an angle of substantially lessthan one hundredand eighty degrees with'respect to'ea'ch'othen'an insulating baseisecuredto the bottom wall of said casing in a plane offset .laterallywith-respectjtothe center line of .said shaft, .a second insulating base secured'within said casingin planes offset upwardly and laterally withrespect to said centerlline,a plurality of stationary contactand terminalmembers secured to each of :saidinsulating; bases, and means for .efiecting oscillatory. movement of. said shaft to bring said .contactorsiintoiand outbibridging engagement with said stationary; con-Z tacts; 1

w z 9. In an enclosed electric switch, in combinati'on a box-likelsheet metal casing. having bottomgsideand endiwalls and an openable cover, an insulating base secured-to the bottom wall of said casing,-::a second insulating .base .1. secured within said casing independently of said first mentioned 1 base. and in spaced relation to .said. bottom wall and said cover, aplurality 10f bridging contactorseach having a pair ;of arms 'arranged atan angle tozeach .other,-an oscillat'able shaft upon which saidconta'ctors are supported within 4 said casing in. insulated relationship: to each other-and independently of each of said gin-- sulating bases, and each .of saidinsulatingbases having a plurality of combinediswitch contact and wiring terminal elements :associated therewith and located substantially. ini the planes thereof respectively, said bridging-contactors bee ing movable jointlyinto and out of engagement with the contact portions ofall of said elements respectively; said contactand terminal. elements being readily accessible uponi opening :of said cover to permit. removal and replacement of. said elements without disturbing saidlcontactors or any of the other'parts of the switch. 4 f:

-10. In an electric switch, in combination,. a box-like sheet metal casing having bottom, side and end walls and an openable cover, ashafthaving the major portion of the length thereof of square cross section, said side walls having alined openings to provide for endwise insertion of said shaft into said casing for bearingengagement with said openings,- a tubular insulating member of square cross section slidable onto said shaft, a plurality of flat'punched sheet metal contactors slidable onto said insulating member-and interlocked therewith for rotation thereby, a .plu-, rality 'of molded insulating cylinders also inter-. locked with said insulating member and arranged on-opposite sides of and between said contactors to space the latter relatively to: each other and to assist in insulating the same, each of saidxcone tactors having a plurality of arms extending. radially froma common center at an angle of substantially less than one hundred and-'eightyidegrees with respect to each other, an insulating base-secured to the bottom wall of said casing in aplaneofiset'laterally with respecttto the center line of said shaft, a second: insulating base secured within said casing in planes ofiset upwardly and-laterally with-respect to said center line,- a plurality of stationary contact and terminal members-secured to each of said .insulating bases, means for effecting: oscillatory movement of said shaftto bring said contactors into and-outof bridging engagement with said stationary contacts, a plurality of fuse receptacles carried by said second mentioned insulating base, saidcover having an opening adapted to register with said fuse -receptacles', a sliding plate movable into and out of register with .saidz'opening; and means providing a releasable interlocking connection between said shaft and said sliding plate to normally insure against movement of 150 the latter out of register with said opening pending movement of said contactors out of bridging engagement with said stationary contacts.

11. 'In an electric switch, in combination, a boxlike sheet metal casing having bottom, side and end walls and an openable cover, a shaft having the major portion-of the length thereof of square cross .section, said side walls having alined openingsto provide for endwise insertion of said shaft into said casing for bearing engagement with said openings, a tubular insulating member of square cross section slidable .onto said shaft, a plurality of flat punched. sheet metal contactors slidable onto said insulating member and interlocked therewith for rotation thereby, a plurality of molded insulating cylinders also interlocked with said insulating member and arranged on opposite sides of and between said contactors to space the latter relatively to' each other and to assist in.insulating the same,ueach of said contactors havingna plurality of arms extending radially froma common center at an angle of substantially less than one hundred and eightydegrees with respect to each other, an insulating base secured to the bottom .wall of said casing in a plane off,- set.laterallytwith respect to the center line of said shaft, a second insulating base secured within said casing in planes offset upwardly and laterally with respect to said center line, a plurality of stationarycontact and terminal members secured to each of said insulating bases, means for. effecting oscillatory movement of said shaft to bring saidcontactors into and out of bridgingengagement withsaid stationary contacts,.apluralityz-of; fuseyreceptacles carried by said second mentioned insulating base, said cover having an opening adapted to register with said fuse receptacles, a sliding plate movable into and out ofu-register with said opening, and means '1 providing a releasable interlocking connection between said shaft and said sliding plate to normally insure against movement of the latter out of register with said opening pending movement of said contactors out of bridging engagement with said stationarycontacts, said sliding plate and said cover having cooperating parts to releasably latch the former in registering relation to said cover opening independently of the interlocking connection aforementioned.

12. In a fused safety switch, in combination, a relatively shallow box-like sheet metal casing having bottom, side and end walls and a hinged cover, an insulating base supported within said casing and spaced upwardly a substantial distance from the bottom wall of the latter, a plurality of fuse receptacles carried by said base, said cover being flat and having an opening to register with said fuse receptacles, a pair of metal strips secured at opposite ends thereof to the inner surface of said cover, a plate slidable between the inner surface of said cover and said metal strips and guided by the latter for movement into andout of registry with said cover opening, said plate having a pair of openings and said metal strips having bosses formed thereon and 'cooperable with said openings to releasably latch said plate in registry with said opening in the cover, wiring terminal elements associated with the opposite ends of the respective fuse receptacles and a pair of molded insulating members of substantially U-shape in horizontal cross section, said insulating members providing bafiles between the fuse receptacles and said terminal elements and preventing access to the latter through said cover opening, a switch mechanism located within said casing, and means associated with said plate and adapted for interlocking engagement with said switch mechanism to normally prevent circuit closing operation of the latter pending movement of said plate into registry with said cover opening.

13. In a fused safety switch, in combination, a box-like sheet metal casing having a fiat main cover member hinged thereto, said cover member having a substantially rectangular opening formed therein to provide access to fuses located within said casing, a pair of strip metal members having the endportions thereof oifset toward the under surface of said covermember and rigidly secured thereto in parallel relation to each other, a metal plate slidable between said strip metal members and the under surface of said cover member into and out of registry with said opening, said plate having flanges extending down-. wardly from opposite sides thereof and engageable with the outer edges of therespective strip metal members to be guided by the latter, said plate having a pair of relatively small openings formed therein, and said strip metal members having bosses formed thereon for cooperation with, said openings to yieldably latchsaid plate in one of its extreme positions.

14. In a fused safety switch, in combination, a box-like sheet metal casing having a flat main cover member hinged thereto, said cover member having a substantially rectangular opening formedtherein to provide access to fuses located within said casing, a pair of strip metal members having the end portions thereof offset toward the under surface of said cover member and rigidly secured thereto in parallel relation to each other, a metal plate slidable between said strip metal members and the under surface of said cove r member into and out of registry with said opening, said plate having flanges extending downwardly from opposite sides thereof and engageable with the outer edges of the respective strip metal members to be guided by the latter, said plate having a pair of relatively small openings formed therein, said strip metal members having bosses formed thereon for cooperation with said openings to yieldably latch said plate in one of its extreme positions, and a switch mechanism located within said casing and operable from the exterior of the latter, said switch mechanism having a part thereof cooperable with one of the flanges on said' plate "to prevent engagement of the switch contacts pending movement of said plate into registry with said cover opening, said flange and said switch part also co-acting to prevent reverse movement of said plate pending disengagement of said switch contacts.'

15. As an article of manufacture, a flat punched sheet metalcontactor for electric switches, said contactor having a body portion of substantially circular contour, a pair of arms extending radially from said body portion, the radial center lines of said arms being spaced from each other by an arc of approximately one hundred and thirtyseven degrees, said body portion having a relatively large substantially square opening formed centrally therein, for cooperation with an oscillatable supporting element of square cross section and one pair of the walls of said opening being arranged in planes parallel to the radial center line of one of said arms.

16. As an article of manufacture, a fiat punched sheet metal contactor for electric switches, said contactor having a body portion of substantially circular contour, a pair of arms extending radially from said body portion, the radial center lines of said arms being spaced from each other by an arc of approximately one hundred and thirtyseven degrees, said body portion having a relatively large substantially square opening formed centrally therein, one pair of the walls of said opening being arranged in planes parallel to the radial center line of one of said arms, and the non-adjacent edges of the respective arms being chamfered to faciliate entry thereof into cooperative engagement with resilient stationary contacts of suitable form.

17. As an article of manufacture, a fuse bafile wall comprising a molded insulating member of substantially U-shape in horizontal cross section, said member being adapted to partially surround a plurality of receptacles for fuses of the cartridge type, said member having channels in the bottom surface thereof to provide clearance for wiring terminal bus members of suitable form, and lugs formed integrally with said member at opposite ends thereof, said lugs being formed to provide for releasable attachment thereof to a suitable support.

18. In a device of the character described, in combination, an insulating base, a plurality of longitudinally alined pairs of clips for fuses of the cartridge type secured to said base, wiring terminal bus members secured to the respective clips and projecting longitudinally therefrom, a pair of molded insulating members of like form, each of said insulating members being of substantially U-shape in horizontal cross section, said insulating members being secured to said base with the open ends thereof opposed to but substantially spaced from each other to facilitate removal of fuses from the respective pairs of clips, said insulating members having the end wall portions thereof interposed between said clips and their respective wiring terminals, and said insulating members having channels in the bottom surfaces thereof respectively to accommodate the bus portions of said terminals.

RALPH A. MILIERMASTER. 

